Perhaps the best overall framework to make sense of creatures as possessing interiority is the organismic philosophy of Alfred North Whitehead. Instead of regarding existence as comprised entirely of substances ricocheting off one another steel balls in an arcade game,
Whitehead believed we and all beings are fundamentally experiential. He agreed with William James who said existing beings are “drops of experience.”
Thomas Berry identifies the interiority issue when he says, “the universe is composed of subjects to be communed with not objects to be exploited.” Subjects have interiority.
We make better sense of both simple and complex creatures if we place priority upon mentality, response, choice, valuing, and more. The mechanization mentality ignores or even denies these capacities fundamental to organisms. We must place interiority before mechanism.